Not at all surprising or unusual, really. Look here:
http:://www.freakonomics.com/2011/05/17/the-neuroscience-behind-sexual-desire-authors-of-a-billion-wicked-thoughts-answer-your-questions/

"Here are some of our findings: heterosexual men like shemale porn, large-penis porn, and fantasies of their wives sleeping with other men. Gay male sexuality is almost identical to straight male sexuality. Women prefer stories to visuals, though women who do prefer visuals tend to have a higher sex drive, exhibit greater social aggression, and are more comfortable taking risks. Men prefer overweight women to underweight women. Heterosexual women like stories about two masculine men sharing their tender side and having sex. Porn featuring women in their 40s, 50s, and 60s is popular among men both young and old. For women, online erotica is often a social enterprise, while for men it?s almost always a solitary one. Most men are wired to be aroused by sexual dominance and most women are wired to be aroused by sexual submission, though a large minority of straight men (and a majority of gay men) prefer the sexually submissive role, and a small minority of women prefer the sexually dominant role."

There is a lengthy thread here entitled something to the effect of liking cock, but not men... I'm sure a search would turn it up. It has LOTS of similar responses.

It means that you like to look at other men's dicks and that you are completely normal. ALL MEN, gay, bisexual and straight, like to look at other guys' dicks and like to watch other guys reach a climax and ejaculate. It's a guy thing.

When we watch another man reach his climax we are living vicariously thru him. We are experiencing his orgasm along with him. Let's face it, even the most potent of us can only climax a limited number of times, but we can watch a hundred other men climax and ejaculate and still want more.

Well said oldbugle. That is how I feel for sure.

I don't think it 'means' anything. It's quite natural to find sex, and anything to do with sex, arousing. And, what is more sexual than a healthy functioning penis in full erection and ready for intercourse? As penis owners we have a 'pro' interest in other specimens and like to see a magnificent example,...as simple as that!